The present invention relates to implantable tissue and, more particularly to a curved implantable sheath and to a method for making a curved sheath.
Various configurations of implantable structures are employed to help repair diseased and malformed organs and other tissue. By way of example, congenital cardiac malformations as well as other diseased conditions, require treatment, which can include drug therapy and/or surgery. Often times, it is necessary to replace or reconstruct an artery or other major vessel, such as the aorta or pulmonary artery.
In one particular condition, known as hypoplastic left heart syndrome, severe aortic valve hypoplasia and/or aortic valve atresia develop. As a result of such conditions, the aorta may be significantly underdevelop, providing a rudimentary ascending aorta having a diameter of about one to about four millimeters. Also as a consequence of limited outflow from the heart, the left ventricle develops abnormally and may be virtually absent.
Because certain curved shapes are difficult to reproduce, a generally flat sheath of biocompatible tissue typically is used for many types of procedures. In other cases a homograft, such as from a cadaver is used.
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is intended to neither identify key or critical elements of the invention nor delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
One aspect of the present invention provides a method for making a curved implantable sheath. A sheet of flexible material is urged into engagement with a member having a curved surface of a desired configuration. The sheet and member are placed in a fixation solution so that the sheet assumes the configuration of the surface engaged thereby.
Another aspect of the present invention provides a method for making a sheath having a curved contour. The method includes mounting a sheet of a biological tissue material to an elongated member having a curved exterior portion. The sheet and elongated member are placed in a fixation solution so that at least part of the sheet is fixed to a configuration corresponding to the exterior portion of the elongated member. The sheet is separated from the elongated member to provide an elongated sheath of substantially biocompatible material having a desired curved contour.
According to another aspect of the present invention, the sheet can be formed to have a generally C-shaped cross section.